/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package org.dom4j.dom;

import java.util.List;

import org.dom4j.Branch;
import org.dom4j.CharacterData;
import org.dom4j.Document;
import org.dom4j.DocumentType;
import org.dom4j.Element;
import org.dom4j.Node;

import org.w3c.dom.DOMException;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.NodeList;

/**
 * <p> <code>DOMNodeHelper</code> contains a collection of utility methods for
 * use across Node implementations. </p>
 * 
 * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
 * @version $Revision: 1.2 $
 */
public class DOMNodeHelper
{
   public static final NodeList EMPTY_NODE_LIST = new EmptyNodeList();

   protected DOMNodeHelper()
   {
   }

   // Node API
   // -------------------------------------------------------------------------
   public static boolean supports(Node node, String feature, String version)
   {
      return false;
   }

   public static String getNamespaceURI(Node node)
   {
      return null;
   }

   public static String getPrefix(Node node)
   {
      return null;
   }

   public static String getLocalName(Node node)
   {
      return null;
   }

   public static void setPrefix(Node node, String prefix) throws DOMException
   {
      notSupported();
   }

   public static String getNodeValue(Node node) throws DOMException
   {
      return node.getText();
   }

   public static void setNodeValue(Node node, String nodeValue)
      throws DOMException
   {
      node.setText(nodeValue);
   }

   public static org.w3c.dom.Node getParentNode(Node node)
   {
      return asDOMNode(node.getParent());
   }

   public static NodeList getChildNodes(Node node)
   {
      return EMPTY_NODE_LIST;
   }

   public static org.w3c.dom.Node getFirstChild(Node node)
   {
      return null;
   }

   public static org.w3c.dom.Node getLastChild(Node node)
   {
      return null;
   }

   public static org.w3c.dom.Node getPreviousSibling(Node node)
   {
      Element parent = node.getParent();

      if(parent != null)
      {
         int index = parent.indexOf(node);

         if(index > 0)
         {
            Node previous = parent.node(index - 1);

            return asDOMNode(previous);
         }
      }

      return null;
   }

   public static org.w3c.dom.Node getNextSibling(Node node)
   {
      Element parent = node.getParent();

      if(parent != null)
      {
         int index = parent.indexOf(node);

         if(index >= 0)
         {
            if(++index < parent.nodeCount())
            {
               Node next = parent.node(index);

               return asDOMNode(next);
            }
         }
      }

      return null;
   }

   public static NamedNodeMap getAttributes(Node node)
   {
      return null;
   }

   public static org.w3c.dom.Document getOwnerDocument(Node node)
   {
      return asDOMDocument(node.getDocument());
   }

   public static org.w3c.dom.Node insertBefore(Node node,
      org.w3c.dom.Node newChild, org.w3c.dom.Node refChild) throws DOMException
   {
      if(node instanceof Branch)
      {
         Branch branch = (Branch) node;
         List list = branch.content();
         int index = list.indexOf(refChild);

         if(index < 0)
         {
            branch.add((Node) newChild);
         }
         else
         {
            list.add(index, newChild);
         }

         return newChild;
      }
      else
      {
         throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR,
            "Children not allowed for this node: " + node);
      }
   }

   public static org.w3c.dom.Node replaceChild(Node node,
      org.w3c.dom.Node newChild, org.w3c.dom.Node oldChild) throws DOMException
   {
      if(node instanceof Branch)
      {
         Branch branch = (Branch) node;
         List list = branch.content();
         int index = list.indexOf(oldChild);

         if(index < 0)
         {
            throw new DOMException(DOMException.NOT_FOUND_ERR,
               "Tried to replace a non existing child " + "for node: " + node);
         }

         list.set(index, newChild);

         return oldChild;
      }
      else
      {
         throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR,
            "Children not allowed for this node: " + node);
      }
   }

   public static org.w3c.dom.Node removeChild(Node node,
      org.w3c.dom.Node oldChild) throws DOMException
   {
      if(node instanceof Branch)
      {
         Branch branch = (Branch) node;
         branch.remove((Node) oldChild);

         return oldChild;
      }

      throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR,
         "Children not allowed for this node: " + node);
   }

   public static org.w3c.dom.Node appendChild(Node node,
      org.w3c.dom.Node newChild) throws DOMException
   {
      if(node instanceof Branch)
      {
         Branch branch = (Branch) node;
         org.w3c.dom.Node previousParent = newChild.getParentNode();

         if(previousParent != null)
         {
            previousParent.removeChild(newChild);
         }

         branch.add((Node) newChild);

         return newChild;
      }

      throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR,
         "Children not allowed for this node: " + node);
   }

   public static boolean hasChildNodes(Node node)
   {
      return false;
   }

   public static org.w3c.dom.Node cloneNode(Node node, boolean deep)
   {
      return asDOMNode((Node) node.clone());
   }

   public static void normalize(Node node)
   {
      notSupported();
   }

   public static boolean isSupported(Node n, String feature, String version)
   {
      return false;
   }

   public static boolean hasAttributes(Node node)
   {
      if((node != null) && node instanceof Element)
      {
         return ((Element) node).attributeCount() > 0;
      }
      else
      {
         return false;
      }
   }

   // CharacterData API
   // -------------------------------------------------------------------------
   public static String getData(CharacterData charData) throws DOMException
   {
      return charData.getText();
   }

   public static void setData(CharacterData charData, String data)
      throws DOMException
   {
      charData.setText(data);
   }

   public static int getLength(CharacterData charData)
   {
      String text = charData.getText();

      return (text != null) ? text.length() : 0;
   }

   public static String substringData(CharacterData charData, int offset,
      int count) throws DOMException
   {
      if(count < 0)
      {
         throw new DOMException(DOMException.INDEX_SIZE_ERR,
            "Illegal value for count: " + count);
      }

      String text = charData.getText();
      int length = (text != null) ? text.length() : 0;

      if((offset < 0) || (offset >= length))
      {
         throw new DOMException(DOMException.INDEX_SIZE_ERR,
            "No text at offset: " + offset);
      }

      if((offset + count) > length)
      {
         return text.substring(offset);
      }

      return text.substring(offset, offset + count);
   }

   public static void appendData(CharacterData charData, String arg)
      throws DOMException
   {
      if(charData.isReadOnly())
      {
         throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR,
            "CharacterData node is read only: " + charData);
      }
      else
      {
         String text = charData.getText();

         if(text == null)
         {
            charData.setText(text);
         }
         else
         {
            charData.setText(text + arg);
         }
      }
   }

   public static void insertData(CharacterData data, int offset, String arg)
      throws DOMException
   {
      if(data.isReadOnly())
      {
         throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR,
            "CharacterData node is read only: " + data);
      }
      else
      {
         String text = data.getText();

         if(text == null)
         {
            data.setText(arg);
         }
         else
         {
            int length = text.length();

            if((offset < 0) || (offset > length))
            {
               throw new DOMException(DOMException.INDEX_SIZE_ERR,
                  "No text at offset: " + offset);
            }
            else
            {
               StringBuffer buffer = new StringBuffer(text);
               buffer.insert(offset, arg);
               data.setText(buffer.toString());
            }
         }
      }
   }

   public static void deleteData(CharacterData charData, int offset, int count)
      throws DOMException
   {
      if(charData.isReadOnly())
      {
         throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR,
            "CharacterData node is read only: " + charData);
      }
      else
      {
         if(count < 0)
         {
            throw new DOMException(DOMException.INDEX_SIZE_ERR,
               "Illegal value for count: " + count);
         }

         String text = charData.getText();

         if(text != null)
         {
            int length = text.length();

            if((offset < 0) || (offset >= length))
            {
               throw new DOMException(DOMException.INDEX_SIZE_ERR,
                  "No text at offset: " + offset);
            }
            else
            {
               StringBuffer buffer = new StringBuffer(text);
               buffer.delete(offset, offset + count);
               charData.setText(buffer.toString());
            }
         }
      }
   }

   public static void replaceData(CharacterData charData, int offset,
      int count, String arg) throws DOMException
   {
      if(charData.isReadOnly())
      {
         throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR,
            "CharacterData node is read only: " + charData);
      }
      else
      {
         if(count < 0)
         {
            throw new DOMException(DOMException.INDEX_SIZE_ERR,
               "Illegal value for count: " + count);
         }

         String text = charData.getText();

         if(text != null)
         {
            int length = text.length();

            if((offset < 0) || (offset >= length))
            {
               throw new DOMException(DOMException.INDEX_SIZE_ERR,
                  "No text at offset: " + offset);
            }
            else
            {
               StringBuffer buffer = new StringBuffer(text);
               buffer.replace(offset, offset + count, arg);
               charData.setText(buffer.toString());
            }
         }
      }
   }

   // Branch API
   // -------------------------------------------------------------------------
   public static void appendElementsByTagName(List list, Branch parent,
      String name)
   {
      final boolean isStar = "*".equals(name);

      for(int i = 0, size = parent.nodeCount(); i < size; i++)
      {
         Node node = parent.node(i);

         if(node instanceof Element)
         {
            Element element = (Element) node;

            if(isStar || name.equals(element.getName()))
            {
               list.add(element);
            }

            appendElementsByTagName(list, element, name);
         }
      }
   }

   public static void appendElementsByTagNameNS(List list, Branch parent,
      String namespace, String localName)
   {
      final boolean isStarNS = "*".equals(namespace);
      final boolean isStar = "*".equals(localName);

      for(int i = 0, size = parent.nodeCount(); i < size; i++)
      {
         Node node = parent.node(i);

         if(node instanceof Element)
         {
            Element element = (Element) node;

            if((isStarNS
               || (((namespace == null) || (namespace.length() == 0)) && ((element
                  .getNamespaceURI() == null) || (element.getNamespaceURI()
                  .length() == 0))) || ((namespace != null) && namespace
               .equals(element.getNamespaceURI())))
               && (isStar || localName.equals(element.getName())))
            {
               list.add(element);
            }

            appendElementsByTagNameNS(list, element, namespace, localName);
         }
      }
   }

   // Helper methods
   // -------------------------------------------------------------------------
   public static NodeList createNodeList(final List list)
   {
      return new NodeList()
         {
            public org.w3c.dom.Node item(int index)
            {
               if(index >= getLength())
               {
                  /*
                   * From the NodeList specification: If index is greater than
                   * or equal to the number of nodes in the list, this returns
                   * null.
                   */
                  return null;
               }
               else
               {
                  return DOMNodeHelper.asDOMNode((Node) list.get(index));
               }
            }

            public int getLength()
            {
               return list.size();
            }
         };
   }

   public static org.w3c.dom.Node asDOMNode(Node node)
   {
      if(node == null)
      {
         return null;
      }

      if(node instanceof org.w3c.dom.Node)
      {
         return (org.w3c.dom.Node) node;
      }
      else
      {
         // Use DOMWriter?
         System.out.println("Cannot convert: " + node + " into a W3C DOM Node");
         notSupported();

         return null;
      }
   }

   public static org.w3c.dom.Document asDOMDocument(Document document)
   {
      if(document == null)
      {
         return null;
      }

      if(document instanceof org.w3c.dom.Document)
      {
         return (org.w3c.dom.Document) document;
      }
      else
      {
         // Use DOMWriter?
         notSupported();

         return null;
      }
   }

   public static org.w3c.dom.DocumentType asDOMDocumentType(DocumentType dt)
   {
      if(dt == null)
      {
         return null;
      }

      if(dt instanceof org.w3c.dom.DocumentType)
      {
         return (org.w3c.dom.DocumentType) dt;
      }
      else
      {
         // Use DOMWriter?
         notSupported();

         return null;
      }
   }

   public static org.w3c.dom.Text asDOMText(CharacterData text)
   {
      if(text == null)
      {
         return null;
      }

      if(text instanceof org.w3c.dom.Text)
      {
         return (org.w3c.dom.Text) text;
      }
      else
      {
         // Use DOMWriter?
         notSupported();

         return null;
      }
   }

   public static org.w3c.dom.Element asDOMElement(Node element)
   {
      if(element == null)
      {
         return null;
      }

      if(element instanceof org.w3c.dom.Element)
      {
         return (org.w3c.dom.Element) element;
      }
      else
      {
         // Use DOMWriter?
         notSupported();

         return null;
      }
   }

   public static org.w3c.dom.Attr asDOMAttr(Node attribute)
   {
      if(attribute == null)
      {
         return null;
      }

      if(attribute instanceof org.w3c.dom.Attr)
      {
         return (org.w3c.dom.Attr) attribute;
      }
      else
      {
         // Use DOMWriter?
         notSupported();

         return null;
      }
   }

   /**
    * Called when a method has not been implemented yet
    * 
    * @throws DOMException DOCUMENT ME!
    */
   public static void notSupported()
   {
      throw new DOMException(DOMException.NOT_SUPPORTED_ERR,
         "Not supported yet");
   }

   public static class EmptyNodeList implements NodeList
   {
      public org.w3c.dom.Node item(int index)
      {
         return null;
      }

      public int getLength()
      {
         return 0;
      }
   }
}

/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived
 * from this Software without prior written permission of MetaStuff, Ltd. For
 * written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may
 * "DOM4J" appear in their names without prior written permission of MetaStuff,
 * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
